


Possession

by TheManicMagician



Category: Undertale (Video Game)
Genre: Alternate Universe - Underswap, Aphrodisiacs, Emotional Manipulation, F/M, M/M, Possessive Behavior, Post-Undertale Neutral Route - King Papyrus Ending, Queen Papyrus, Yandere Sans, king sans, skelepreg
Language: English
Status: In-Progress
Published: 2017-09-17
Updated: 2017-09-17
Packaged: 2018-12-30 17:57:11
Rating: Explicit
Warnings: Rape/Non-Con
Chapters: 2
Words: 7,795
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12114120
Author URL: https://archiveofourown.org/users/TheManicMagician/pseuds/TheManicMagician
Summary: Sans has lost much to the human. He’s not letting go of Papyrus.





	1. Chapter 1

Sans shuts off his alarm after the first ring, and sits up in bed. Papyrus had moved out from under his arm sometime in the night. He’s curled near the edge of the bed, his breathing deep and even. The brief blare of the alarm wasn’t enough to rouse him.

Sans reaches over. His fingertips graze against the narrow planes of his brother’s face, before skimming down to give his shoulder a shake. 

“Time to wake up, Papy.”

He’s awake instantly at the sound of Sans’ voice. It’s so different compared to their years in Snowdin, when it’d take ages of pleading and prodding to get him out the door in the morning. They’re both different now, Sans supposes. The human’s rampage took much from them, but also gave them the crown. They’ve been isolated, handed unfathomable responsibility. Both of them have had to adapt to their new roles.

As he does every morning, Sans goes into their shared walk-in closet and carefully selects Papyrus’ outfit. Papyrus needs to be looked after. Without Sans, he’d wear the same threadbare, unwashed outfit he always had before.

Today’s special; they’re meeting with old Snowdin acquaintances. Sans does not want them to get overfamiliar at the reunion, so he choses garments that will emphasize Papyrus’ new status and role. An ankle-length dress, quite similar to what the previous Queen had worn. Its demure cut barely hints at the figure beneath—Papyrus’ body is only to be seen by Sans’ eyes.

Sans returns to the bedroom with the dress draped over one arm, holding it carefully so its hem doesn’t drag over the carpet, clean though it may be. Papyrus has already disrobed, his sleepwear folded neatly at the end of the bed. His ivory bones are long, elegant, their perfection marred only by a thin scar across the front of his neck vertebra. A farewell gift from the human. Sans doesn’t like to look at it.

There’s a slight twitch in Papyrus’ jaw as Sans lays the dress out for him to see, but he utters no complaint. It’s great progress, which Sans elects to promptly reward. 

Sans climbs into his little brother’s lap, and engages him in a deep kiss. Papyrus never moves much when they kiss, leaving Sans to do all the work. Such a lazybones. Maybe Sans should lend him his dating manual, so he can learn how to be better.

Sans breaks off the kiss, and bumps his forehead against Papyrus’.

“Show me your soul, Papy.”

Sans reaches into the hollow space between his brother’s ribcage, hand open. Papyrus’ soul materializes, nestling itself in Sans’ palm. He pulls it out. Now matter how often he gazes upon it, he is always stuck by its simple beauty. Sans plants a tender kiss atop its surface, reveling in how the light touch makes Papyrus shiver.

Sans’ thumbs rub circles into his soul. Papyrus flushes adorably at the stimulation. He can feel heat warming Papyrus’ pelvic girdle. Sans broadcasts feelings into the connection with his brother—supplication, devotion, arousal—and with a gasp Papyrus forms a plump mound of magic for him.

“Very good, Papy.” His brother’s arousal spikes at the praise.

“S-Sans, please,” Papyrus rasps. He wiggles against Sans’ heavy weight atop him, needing friction.

Sans gives his brother’s soul a final firm squeeze, before he returns it to his chest.

“Be patient.”

Sans slips off of him. He rummages beneath their bed, and pulls out a black box. He opens the lock—set to Papyrus’ birthdate—and selects the toy for the day.

When he rejoins his brother on the bed with his prize, Papyrus balks. His legs close, and he scoots back away from him.

“I don’t need that. Please, don’t make me wear it. It won’t fit—”

“Hush,” Sans shushes him. “You know I know what’s best for you. This will protect you.”

He strokes Papyrus’ face soothingly, until his panicked breathing settles again. Then, he returns his attention to the chastity belt in his hand. He’d had it specially made, the straps the finest leather, the size to Papyrus’ exact specifications. Attached to the belt is a thick vaginal plug. It’ll keep Papyrus stimulated throughout the day, keep his sexual magic manifested. But it won’t be enough to make him cum. Sans grabs a bottle of lube from the bedside table, making sure the plug is slick, coated.

“Lie back, and lift your hips.”

Papyrus obeys. Sans wraps the top belt around him, and gestures for him to lower his pelvis again.

Papyrus moans as Sans pushes the plug inside.

“See, that wasn’t so bad.” Sans flicks his clit, just to watch him jolt.

Sans finishes buckling and fastening the rest of the harness. And then comes the most fun part. Sans slides in two small locks, one at the middle of the belt, one to anchor the plug. He clicks both into pace, and puts the one key to both of them in his cell phone inventory.

Papyrus’ hips twitch with his aborted climax as Sans helps him to dress. Its bulky cut obscures any hint of the chastity belt. Sans leads him to the full-length mirror in their bathroom, so Papyrus can see how beautiful he looks.

~*~

After getting dressed in his own magnificent, kingly garb, Sans leads Papyrus by the hand to the banquet hall. As per his request, the servants have prepared a hot breakfast for the royal couple, and left them to serve themselves. Sans indulges in a stack of blueberry pancakes, and sets foods on Papyrus’ plate that he knows he loves: banana nut muffins, honeyed porridge, small tart cakes. Hardly the most healthy, but Papyrus need to be plumped up. Sans will give him whatever foods he wants if it’ll pad out his magic, and protect his brother’s eggshell bones.

Sans spears a cut of pancakes, and pops it into his mouth, chewing briskly; their first meeting of the day is fairly early in the morning. They can’t afford to dawdle. 

He looks up from his breakfast to see that Papyrus has barely picked at his own meal. He’s ripping off small parts of the muffin and pinching them flat between his thumb and forefinger, letting the crumbs roll off onto the plate.

“Papy.”

Papyrus drops his hand, startled. Sans smiles sweetly at him.

“Don’t play with your food.”

Sans watches him pick up the muffin, and take a tiny bite.

Irritation flashes through him. Is Papyrus being deliberately difficult?

Sans grips Papyrus’ wrist and shoves the muffin further into his mouth. Papyrus chokes.

“Eat.” Sans orders.

Sans will cram it down his throat if he has to. He keeps an unrelenting grip on Papyrus’ wrist until he eats the whole thing.

Sans lets go, and watches with satisfaction as Papyrus digs into the remainder of his breakfast with gusto.

~*~

An hour later finds the pair of them at the archway leading into one of the many gardens tucked away within the palace. The throne room felt a bit too formal—they’re meeting with old friends, after all! So instead, he’d had servants bring out appropriate outdoor furniture, for them to discuss matters with a pleasant backdrop.

Sans grabs Papyrus’ hand, tangling their fingers together. Papyrus gives him a brittle smile. There are pearls of sweat dripping down the back of his skull, and a faint dusting of a blush on his cheekbones. If Papyrus behaves well enough throughout their meeting, Sans might reward him.

Papyrus follows him out into the garden. The weather’s warm, and a gentle breeze makes the golden flowers sway.

Papyrus walks with but a hint of awkwardness, an affable grin on his face that betrays nothing.

Their two guests are already seated, but they rise upon the royal couple’s approach. They’re two pillars of the local Snowdin community. Bearnard, a brown bear monster with a keen interest in local politics, and the owner of the town’s favorite watering hole, Muffet.

“Hello, dearie.” The spider greets Papyrus first, before curtseying to the King. Bearnard bows as well.

“Hello, friends!” Sans says, cheerily. Papyrus gives Muffet a small, jerky nod. “Go on, sit down!”

Muffet and Bearnard take their seats on either side of the rectangular table, while Sans and Papyrus sit at the head. Papyrus winces as they sit down, but his expression quickly smoothens out.

“Can I get you anything? Let me get you drinks.” Sans gestures towards a servant, who had been standing at a respectable distance away from the conversation. She nods and disappears back into the castle to fetch refreshments.

“Thank you for seeing us on such short notice, your highness.” Bearnard says.

“You don’t have to call me that,” Sans laughs. “You know us. We’re just Sans and Papyrus, after all.”

“You both look…well.” Muffet says, haltingly. Sans can tell she’s put off by Papyrus’ outfit. The servants had been uncomfortable at first, too. But Sans has made them understand. Papyrus is his judge, his closest advisor, and his Queen.

“So, what seems to be the problem?” Sans asks.

“We’ve been having issues with food deliveries.” Muffet explains. “Supply orders from the capitol keep getting waylaid in Waterfall.”

Bearnard jumps in. “They keep telling us that the food is “accidentally” spilled into the river. One time is unfortunate, but understandable. But Snowdin hasn’t received the last five shipments that were placed.”

“It’s gotten to the point where my café and the general store are giving out whatever reserves we have, and even those are beginning to dwindle.”

“That’s terrible!” Sans says, voice thick with sympathy. He isn’t one to believe the worst in people, but five missing shipments is an awful lot to just be a mistake. “Papy, do you have any experience with this? Have incidents like this happened before?”

All eyes turn to Papyrus. He fidgets at first, uncomfortable under the scrutiny, but eventually speaks. 

“Somethin’ similar happened before, ‘bout three years back. Stuff dissapearin’. People were hoarding and stealing stuff, because there was a rumor going around that another human fell into the Ruins. Turned out to be a false alarm.” Papyrus fiddles with the long white sleeve of his dress. “If I had to guess, I’d say people are still freaked over the last human’s arrival. They’re still panicking.”

It’s understandable. The human had taken all their heroes from them. The Queen and the absent King, the Royal Scientist, the Captain of the Guard, and even their one popstar…all gone. It’s been a little over three months since Sans was elected, but monsters are still scrambling for stability.

“Well, we will not let this continue.” Sans declares. He’s the new King. He has to protect everyone. “I’ll assign guards to the next convoy, and you’ll be reimbursed by the royal treasury for any previous payments on the failed deliveries.”

The Snowdin residents are grateful, and when servants arrive with pitchers of ice water and lemonade, he sends one of them back out to fetch him a pen and paper so he can draw up an official order.

Sans had always gotten along well with Bearnard—tended to get along well with most, in fact—so they keep a companionable conversation flowing. Muffet only interjects occasionally, and Papyrus speaks only when spoken to directly. When the servant returns again with what he requested, he pens a letter to the temporary acting head of the guard. He’ll assign trustworthy guards to protect the trade caravan. After listing his instructions, he signs the bottom of the letter with a characteristic flourish of a signature: The Magnificent King Sans.

Sans doesn’t like how Muffet’s black, beady eyes keep flickering over to Papyrus. One secret that he’s never been able to pry out of his brother is how close he’d been to that spider. He wouldn’t even mind if they had fooled around together. He wouldn’t. But it’s the not knowing that’s killing him.

“I hate to cut this short,” Sans says, apologetic, after passing the signed letter over to Bearnard for him to pocket. “But we should prepare for our next meeting of the day.”

“Of course, of course!” Bearnard squeezes one of Sans’ hands between his two massive paws. “Thank you again, my King.”

“Mweh heh, I told you, call me Sans.”

Bearnard smiles. “Thank you, Sans.”

Sans sees Bearnard off to the front door of the palace, which is quite close to this particular garden, just a few hallways away. Papyrus trails behind with Muffet. Sans wants to tell them to catch up, but Bearnard pulls him back into conversation, and it’d be impolite to interrupt.

It’s not until they’ve reached the threshold of the palace that he thinks to look back again. What he sees makes his magic roil. Papyrus and Muffet have stopped walking altogether, about twenty feet back. They’re speaking, too low for him to hear. Muffet leans over him, her face the picture of concern. One of her hands comes up, and she presses the flat of her palm against his skull, she’s  _ touching _ his Papyrus—

Within a blink Sans is next to them, with a grin and empty sockets. Muffet reels back, startled.

“Muffet, if you’ll excuse us. Good day.”

“Wait!” She says, but Sans has already grabbed Papyrus by the wrist, leading him back into the garden and slamming the door shut behind him. There aren’t any servants or guards in the garden; they are alone.

“What was that?” Sans interrogates him, barely keeping his voice level.

“I-It was nothing.”

“Papyrus.”

“Really!” He insists. “She was just—she saw that I was very f-flushed, she was worried about me!”

“I’ve told you and told you, no one can touch you, only I can touch you,” He can’t get that moment out of his mind, when he had come back from practice with Alphys to see his baby bro dying in the snow, magic bleeding from a knife wound to his neck, left there to die.

Sans turns Papyrus’ soul blue, dropping him to the ground. He’s crushing the flowers, but in the heat of the moment Sans doesn’t care.

“You’re mine,” Sans declares, hiking up Papyrus’ dress. “I’ll prove it as many times as I have to.”

“Sans, no.” Papyrus whimpers. He claws at the ground, churns up the dirt, but he can’t shake Sans’ hold.

Sans removes the key from his inventory, and unlocks both sets of locks. He unbuckles the belt, and slides the chastity belt down. Papyrus cries out as Sans grips the base of the plug and slides it out of him.

Sans tosses the chastity belt to the side. Papyrus’ juices trickle out of his exposed entrance. Sans reaches a hand into his pants. The sight of Papyrus splayed out and defenseless before him already has him worked up. Sans frees his erection, wrapping a hand around it. He palms his cock roughly.

“Sans, not here, please. Someone’ll see us.”

“I don’t care.” Sans growls.

Sans grips Papyrus legs by the backs of his knees, and lifts them, splaying them open. His phalanges tighten on Papyrus’ legs as he pushes in.

Papyrus shrieks. “S-Stop, Sans, it’s—it’s too much!”

Sans rams into him, each thrust making Papyrus rock and jolt. Papyrus is filthy, dirt and pollen staining his clothes, the back of his pelvis. Sans is going to have to scrub every dip and groove of his tailbone to remove all the dirt particles that are getting lodged in there.

Sans pistons inside Papyrus. His brother has never had enough stamina to keep up with Sans’ own energy. His mouth goes slack, eye lights glazing over, unable to struggle.

Sans looks down from Papyrus’ face, to where their magics are joined together. It’s eternally fascinating to him, to watch his cock moving inside Papyrus, stretching him wider.

“S-Sans…”

Papyrus is close. The constant stimulation from having the plug inside him has him desperate for release. His toes curl, his breath hitches as his body tightens—

And Sans slows his pace.

Papyrus lifts his head weakly, meeting Sans’ gaze, his eyes full of confusion.

“I don’t think you deserve a reward after that little stunt, do you?”

“Please, Sans. I’m close…”

“Begging won’t get you anywhere, Papy. Only good behavior.”

“I-I’ll be good. I will!”

Sans pulls out. He’s almost painfully hard, ready to cum himself. But Papyrus needs to learn.

Sans rises, and releases the blue magic hold over his brother.

“On your knees.”

Shakily, Papyrus picks himself up. One of his hands strays down, to attend to his own aching need, but Sans smacks his hand away.

“You won’t cum until I say.” Sans nudges the head of his cock against Papyrus’ cheek, smearing precum over the bone.

Papyrus parts his mouth, and Sans shoves inside. Papyrus gags around his length, but does his best to give him a proper blowjob. Tears bud in his eye sockets. Sans brushes them away with his thumbs. There’s nothing to cry about. This is just some necessary tough love.

Sans groans with satisfaction as Papyrus starts to suck and swallow around him. Sans grips the back of Papyrus’ skull and presses him close, burying his nasal bone against his pelvis.

Sans sighs his brother’s name as he climaxes, cum spurting down Papyrus’ throat, splashing against the insides of his ribs.

Sans pats Papyrus’ skull gratefully, his legs quivering with the aftershocks of his orgasm.

He pulls out. Papyrus is panting for air, the tip of his tongue lolling out of his mouth. His face is flushed, and sticky with cum and tears.

Sans readjusts his pants, then locates the chastity belt. Thankfully the sticky plug had avoided contact with the ground; he brushes off the few crumbs of soil that clung to the harness and returns to Papyrus.

Papyrus starts to protest. “But I haven’t—” 

Sans silences him with a leveled look. He lowers Papyrus back down, into a sitting position, and starts putting the belt back on.

“We have another meeting during lunch. We’re going over the budget with Greensbury.”

Sans pushes the plug back inside him. Papyrus’ hips rock up, but it doesn’t hit deep enough to bring him to orgasm.

“It’s important that we get the particulars of the budget just right. The meeting could take hours.” Sans smiles as he cinches the locks back into place. “If you’re good this time, then afterwards, I’ll let you cum.”

Sans presses his closed teeth to Papyrus’ forehead in a gentle skeleton kiss, as he’s done a thousand times before, and will do a thousand times more.

“Get cleaned up in our room. And remember, I love you, Papy.”

Papyrus’ breath hitches, and he covers his face as he starts to sob.


	2. Chapter 2

**Notes for the Chapter:**

> Warning: This chapter contains sensitive materials.

One evening, after dinner plates are cleared away, the servants bring out one final dish and set it before Papyrus.

“That will be all,” Sans dismisses them.

On the scalloped, gold-trimmed plate is an artisan dessert, a ruby red fruit shaved over spongy pound cake, topped off with a heavy glaze. Sans pushes the plate closer still to Papyrus.

“Go on, try it.” He can barely contain his excitement. It’s not the first time he’s arranged a fancy dessert for his brother, but this one is particularly special.

Papyrus eats mechanically. The dull sheen to his eyes—which crept in one day and never seemed to leave—doesn’t change despite the treat. His poor, sweet little brother. Still grieving for those lost.

Sans reaches out, and places his hand over Papyrus’.

“How is it?” Sans asks.

“It’s warm.”

“The fruit on top is a rare Hotland delicacy.” Sans explains. “It needs to remain at ninety degrees constantly before it is served. A vulkin transported the fruit himself, and the head chef stored it in a hot fridge until today. Isn’t that interesting?”

Papyrus nods.

Sans’ thumb brushes against Papyrus’ hand.

“Papy, I’ve been thinking. I’ve seen how lonely you’ve been lately. How sad.”

Papyrus’ eye sockets widen. “N-No, I’m fine.” He stammers. “I’m happy. I’m with you.”

“Don’t worry. I’m not angry with you. I understand how hard it’s been for you, trying to adjust to our new life here. I know you miss all our old friends; I do, too. Sometimes when I wake up in the morning, I’ve put on half my battle body before I realize what I’m doing. What you need right now is companionship, but I can’t be with you all the time. The kingdom needs me.”

Papyrus has been restricted to the castle grounds, unless Sans accompanies him. Protective wards have been erected as well—no teleportation in or out of the castle boundaries. If another human falls down, of course Sans has to be there to protect his Queen!

(The fact that these limits keep Papyrus from visiting Muffet is purely coincidental.)

“But I have a solution.” Sans leans forward, buzzing with excitement. “Let’s have a child.”

Papyrus coughs, nearly choking on his forkful of dessert.

“Wh-What?” Papyrus asks, hoarse with disbelief. “We can’t—”

“Just think about it! Imagine our babybones, running through the castle halls. Growing up in the safest environment, with all the best tutors. They won’t ever want for anything. The Underground needs a new start, a new beginning, something to hope for. And you wouldn’t be left alone. You’d have a child. Our child.” Sans’ voice is thick with love at just the thought.

“Greensbury would never agree to it.” It’s a feeble protest.

“Never mind my advisor. Never mind the Underground. We’ll be happy. And the rest of them will come to accept and love our darling prince. Or princess.” Sans giggles. “Oh, I wonder which will be better! Maybe we should try for one of each!”

Papyrus is just staring at him, at a loss for words.

“Finish your dessert, Papy.”

Sans watches him keenly, making sure his brother polishes off the rest of the plate.

Sans grins widely. The fruit in Papyrus’ dessert is the rare Devil’s Kiss, meant to induce a heat in the consumer. Sans had waited patiently for Papyrus to fall into his heat naturally, but after months of close proximity (and delightful sexual activity) with no result, Sans simply couldn’t wait any longer. The Devil’s Kiss will help his brother along, ease him into the heat.

He reassures Papyrus what a great mother he’ll make.

~*~

Sans gives a pleased groan as he wakes, a heavy sweetness in the air. Papyrus is still asleep beside him, curled on his side, facing Sans. He’d kicked the covers off him in his sleep, but is still sweating. Sans presses the back of his hand to Papyrus’ flushed cheek—he’s hot to the touch.

Sans lets slip a relieved sigh. He’d stayed up and watched Papyrus the night after he ate the Devil’s Kiss. He’d patted his brother’s skull and whispered to him the whole night through, talking of all the great things they’ll do with their future child. He’d been quietly devastated when the night passed without any changes.

But four days later, here they are. It must’ve just taken a few days longer than Sans expected for the fruit to run through Papyrus’ system, and for his body to prepare itself for a heat.

Sans hops out of bed, not even bothering to throw a night robe on over his pajamas.

At the end of the hallway that leads to the royal bedroom, two guards are posted. They salute as Sans approaches, neither commenting on his state of dress.

“Notify my advisor that I’ll be cancelling all my appointments today. And cancel anything on the Queen’s itinerary. Have the maids send up water and fresh fruit to the bedroom in the evening, and instruct Mary to send up her special sea tea now. Afterwards, you can dismiss yourselves.”

The guards exchange a glance.

“It is our duty to make sure you are protected at all times.”

“While I appreciate your loyalty, I assure you your concern is unwarranted. I’m the King, after all. Surely I can defend myself.” There’s a grit beneath his pleasant tone.

The soldiers bow.

“Very well, my King.”

Papyrus’ first heat is special. Sacred. Sans doesn’t want anyone to overhear anything—Papyrus’ cries of ecstasy are for him to treasure, and him alone.

Sans returns to the bedroom, and soon after the tea is sent up to him. He thanks the maid, and locks the door behind her.

He blows lightly on the hot tea before gulping it down. This isn’t the average sea tea, scooped up from the marsh and put in a pot to boil.  This blend has rare herbs meant to help with heats, to give a monster the stamina to keep up with their mate, and to encourage virility. It tastes hot, earthy. He’d certainly eaten worse at Alphys’ house. Sans sets the mug aside, and disrobes. Now, everything is in place.

Sans climbs onto the bed. Papyrus, bless his heart, hasn’t stirred in all this time. Ever the lazybones. Gently, he turns Papyrus so he’s on his back. Some time during the night, Papyrus’ ectobody had manifested as he’d entered his heat. The swells of his new breasts peek out over the top of his loose black tank. Sans lifts his shirt. The ectoplasm extends from Papyrus’ chest, all the way down to his knees. Sans rests his hand on his soft stomach, pudgy from indulgence in too many sweets. Skeletons don’t normally have tangible flesh, organs. It’s unneeded, and keeping ectoflesh sustained and solid is incredibly taxing. But Papyrus’ magic has constructed all Sans will need to ensure the heat ends in pregnancy.

Sans’ hand slips up Papyrus’ shirt, to grasp at his breasts. They’re on the smaller side; he cups them easily in his hands. His thumbs circle Papyrus’ pert nipples. His brother sighs happily, but the light stimulation still isn’t enough to rouse him.

Sans doesn’t want him to wake just yet. Even in his heat, Sans is sure Papyrus will be embarrassed at his reaction to Sans’ touch. For now, he can drink in Papyrus’ delectably unrestrained responses.

Sans moves downwards. Papyrus’ legs have fallen open at Sans’ caresses. His mouth waters as Papyrus’ tangy scent wafts up.

Gently, he pulls off Papyrus’ boxers, and lets them drop to the floor. He squeezes his hands around Papyrus’ thick thighs, reveling in the texture. Papyrus will have magic for spare for their child.

Papyrus’ fluids have dripped down the sides of his thighs. Sans presses quick kisses to his inner thigh, moving inwards to the dewy source.

Papyrus groans as Sans’ tongue swirls along his outer folds. Papyrus’ taste is sweeter, more overpowering than it usually is. Just the smell alone is beginning to affect Sans, his arousal manifesting into the form of an already-stiffening cock.

Sans slips his tongue inside Papyrus. A full-body shiver runs through him, and his thighs continue to quiver as Sans gently slides his tongue in and out.

Not only is Papyrus’ scent intensified, but also his sensitivity. Early on in their relationship, Sans needed to use every trick in his dating book and more to coax his brother to his climax. He’s gotten better with time and experimentation, but he’s never gotten such a strong reaction before from such minimal stimulation. Sans licks at the smear of fluid on his chin, and makes a note to look into more generalized aphrodisiacs for everyday use.

Sans’ teeth scrape lightly against Papyrus’ clit. Papyrus jolts at the touch, but miraculously doesn’t wake up. Sans rubs at Papyrus’ clit with his fingers, drinking in every twitch and sigh his hand evokes. His brother must be having a very pleasant dream.

There’s a giddy joy in this, pleasing Papyrus while he’s unaware. He feels like a schoolboy getting away with cheating on an exam.

Sans holds his cock in one hand. It throbs with need. With his free hand, he grabs one of Papyrus’ legs, lifting it and spreading him open enough for Sans to align the head of his erection with Papyrus’ entrance. Keeping his eyes on his brother’s sleeping face, he slowly nudges in the tip. It takes all of his self-control to not slam inside. Instead, he keeps his thrusts shallow, pushing the tip of his cock in and out, in and out. Papyrus has started to drool out of the side of his mouth.

Sans pulls out entirely, bending down to nuzzle his brother’s neck. His hot breath blows against the thin raised scar from the human’s knife.

Sans’ hands find Papyrus’ breasts through the thin fabric of his shirt, squeezing and stroking. Papyrus is flushed with life beneath him. Vibrantly alive, here with him.

Sans can’t hold back any longer. He lines up with Papyrus again and sheaths himself inside with one deep, hard thrust.

Papyrus’ eyes shoot open. Suddenly tense, he clenches down tight around Sans’ member.

“Stars, Papy…” Sans breathes.

Papyrus pulls off Sans in his half-awake panic before Sans grips him tightly by the hips and slams them back together.

Papyrus’ head falls back against the mattress as his hips jerk up.

“Wh-Why?”

“Isn’t it wonderful? Your heat started.” Sans pounds into him, and licks at Papyrus’ exposed collarbone.

“But…” His darling brother is overwhelmed. It must be difficult to think clearly, his mind clouded with the heat. He rolls his hips with Sans’ movement. Submitting.

“Your body knew what we both wanted.” Sans kisses him before murmuring: “I’m going to give it to you. You’re going to be so full with my cum. Gonna fill you up ‘till you’re pregnant.”

Lust dances in Papyrus’ eyes. His usual shyness is stripped away, Sans’ priming of his heat has seen to that.

When Sans cums, Papyrus clings to him, presses him close. Sans stops thrusting as his seed floods his brother’s pussy. The tea he drank keeps him erect, so after a momentary pause he starts moving again. Papyrus cries tears of overstimulation, and Sans wipes them away.

Papyrus, oversensitive, orgasms five times before his fragility gets the better of his heat. He falls mostly unresponsive, a glazed look in his eyes as Sans continues to pump into him until he’s got nothing left to give.

When Sans pulls out, hours later, semen drips steadily from Papyrus’ entrance. Sans doesn’t let it go to waste, scooping it up and massaging his sticky fingers against Papyrus’ pussy, keeping the cum plugged up inside him.

Sans strokes Papyrus’ stomach, imagining it swollen with their child, the tangible proof of their unyielding devotion to each other.

Sans presses a kiss to Papyrus’ slack jaw. “I love you.”

~*~

Papyrus stretches, groaning as the movement makes his spine pop. He’s been sitting in one position for too long, hunched over a thick theoretical physics textbook and his scratch paper. The library is an undisputable perk of castle living; Papyrus now has access to just about every published text in the Underground. Books are copied by scribes, and after being bound are distributed to various libraries. The few soggy books he scavenged from the dump are paltry compared to the shelves and shelves of thick texts now at his disposal. Solutions he’d been scratching his skull over for years are now laid out plainly by printed out theories from both humans and monsters alike. It wouldn’t be in his nature to do anything productive with his theories—but it’s a nice hobby. Keeps his mind sharp.

Papyrus massages his stomach. It’s been two weeks since—since. There’s no sign of a souling yet, but it’s telling that his ectoplasmic form hasn’t dissipated since his heat. Sans is confident that he’s already with child, and has already chipped away at his scant freedoms. He’d had to beg for a simple day to himself in the library. If this is what Sans is like already…

Using the table for leverage, he pushes himself upright and gathers the books. A librarian is instantly at his side. She plucks the weighty books from his hands before he can protest, and walks off to place them on their proper shelves.

Papyrus eyes one of the several unobtrusive nooks in the large library. He surreptitiously looks around. No librarians are nearby, all busy sorting books. No one pays him any mind.

Nonchalantly, he makes his way to a particular nook. There’s a small window, which is cracked the slightest bit to let air in. A circular table and chair are set nearby, for anyone who wants to read by the artificial daylight.

Papyrus sits, leaning the chair back up against the brick. After a moment, a spider, no larger than one of his phalanges, scuttles through the open crack in the window, and crawls down to perch on his shoulder.

“Hey there, little buddy.”

The spider chitters happily, offering up the lone cigarette it carried here. There’s a lilac spider emblem stamped onto the white paper, Muffet’s signature. She grows the tobacco herself; Papyrus has long been a fan of its unusually sweet bite.

Regretfully, he declines the offered cigarette.  

“’fraid I can’t smoke anymore.” He lifts up his sweatshirt, just enough to expose a sliver of his stomach. “Gotta souling to think about now.”

The spider trills, but soon quiets as it notices Papyrus’ joyless expression. It chitters questioningly.

“Look, just…tell Muff thanks but I won’t be needing any drop-offs for the next couple months. Make that seven months.” Skeleton pregnancy terms are on the longer side compared to most monsters, nearly human length. “Christ. I can’t believe…”

The spider cuddles close to him and he realizes he’s teared up. He wipes at his eyes.

“Sorry. Tell Muff I’ll manage. Somehow.”

He still doesn’t understand why he’d entered his heat at all. He’d only ever had one heat in his life before now. Muffet had coached him, helped him with deft, nimble fingers.

A monster only goes into a heat cycle when they’re comfortable, and ready to mate with their beloved. What he has with Sans is a sham, a warped version of brotherly love. It shouldn’t have happened, and yet…well, it did. And the magic took. Which would mean…

Papyrus really wants that cigarette.

But he doesn’t stop the spider from webbing the cigarette securely to its back. Papyrus lifts the spider up to the sill, and it scampers out again.

Not long after Muffet’s visit to the castle with Bearnard on behalf of Snowdin, spiders started crawling out of every cobwebbed cranny in the castle. Their chatter is too squeaky for him to parse out, but he can understand their tone of voice easily enough. They’ve ferreted him gifts; cigarettes Sans refuses to provide him, peppermint-cinnamon candies that taste like home.

On occasion the spider messengers come carrying notes from Muffet, updating him on day to day activities of Snowdin. He clings to this shred of normalcy like a lifeline; it’s the one thing that’s kept him sane all these months as Sans continued to tighten his grip.

The day after his discussion with the spider in the library, another drops down on his shoulder and slips him a note.

Muffet is planning his escape.

~*~

Papyrus heaves. Globs of half-digested magic splatter on the porcelain shell of the toilet. He wipes at his mouth, weakly, before his stomach rebels again, stringy bile dripping from his mouth. He hadn’t expected the nausea of morning sickness to be so intense, or for it to drain him so completely. The bathroom door creaks open, and Papyrus fumbles for the toilet handle, in a futile attempt to flush the evidence.

“Oh, Papy!” Sans crouches down beside him, his eye lights burning with concern.

“Hey, bro.” His voice is hoarse.

Sans rubs his back. “The doctor said this would start happening soon. Are you feeling better now? Or do you want to stay here a little longer?”

Papyrus’ hand settles on his stomach, the bulge of the souling prominent in his maternity shirt. The souling, little more than a pinprick at this point, emits a pleasant heat. He waits for a moment, to see if his gorge will rise again, but his stomach seems to have settled from its volatile state.

“I’ll have the maids bring up oatmeal.”

Just the word brings the visceral smell of oats and cinnamon to mind, too thick and overpowering—

Sans supports him as he vomits again.

“My mistake,” Sans apologizes, once Papyrus has coughed out several more strands of magic. “Just tell me what you want. Anything. I’ll get it for you.”

“I want to go to bed,” Papyrus croaks.

Sans frowns—Papyrus knows that isn’t quite what he’d meant, but Papyrus doesn’t think he could stomach (heh) the thought of food right now.

“Very well.” Sans wipes Papyrus’ face clean, before picking him up bridal style.

Papyrus yelps, alarmed, clutching tightly to Sans.

“I-I can walk!” He squeaks.

Sans chuckles, carrying him from the bathroom.

“Let me take care of you. Something like this is nothing for the Magnificent King Sans, mweh heh heh!”

Sans lays Papyrus on the bed with great care. He fluffs the pillows and tugs the covers around him.

Papyrus is struck with a bittersweet nostalgia. Sans used to fuss over him like this when he’d gotten sick as a babybones. He’d made mountains out of molehills; Papyrus came home once with a sniffle and Sans responded by piling every blanket in the house on top of him, and force fed him healthy but disgusting herbal remedies.

Papyrus had tolerated Sans’ worrying—Sans was always fretting over his lower-than-average stats—and part of him secretly enjoyed it. It felt good to be cared for, to be loved so plainly.

(Maybe it had been his fault things turned out like this, in a way. He’d encouraged this behavior. He’d never said no.)

Papyrus shuts his eyes. Just for a moment, he wants to pretend he’s home in Snowdin, in his own bed, and Sans is over-worrying about a simple cold.

“Can you sit up, Papy?” Sans nudges him out of the fantasy, a cup of cool water in hand. Papyrus reaches for the glass, but Sans is insistent on raising it to his mouth, helping him drink.

Sans does what he does out of love. That makes it worse.

~*~

Papyrus toddles his way over to the secluded nook in the library. Nearly six months pregnant, he cannot wait for the child to get out of him. His spine aches perpetually. He feels bloated, and the slightest movement leaves him breathless and sweating. But worst of all, once it had become difficult for Papyrus to stand on his own, Sans appointed him a round the clock nanny to keep an eye on him whenever Sans wasn’t there. She was sweet, but it was stressful and irritating to never truly get a moment alone to himself.

Right now, he’s gotten himself a moment of freedom. He sent the nanny to the kitchens, to fetch his latest craving—large pickles slathered with ketchup. It should take her at least ten minutes to get to the kitchen and back, giving him a short window of opportunity.

A cluster of spiders are already waiting for him at the nook, and they offer him up a scroll. He unfurls it and reads quickly. A few weeks back he informed Muffet of an opportunity—the royal couple are to be present at the annual parade through New Home. Sans had been reluctant, at first, to bring Papyrus when he’s so close to the baby’s birth. But Papyrus had managed to sway him. He was going stir crazy in the castle, and wouldn’t it be nice to let monsterkind see their hope for the future?

The parade draws monsters from every corner of the Underground, a crowd like nothing else. It wouldn’t be suspicious at all for Muffet to be present. And even with Sans’ security measures, the crowd would prove difficult to navigate and comb once Papyrus was “lost”.

The plan is simple enough. Once the parade crosses into Muffet’s territory, he’ll fake nausea, and ask to be escorted from the parade route by a small group of guards to get some privacy. He’ll lead them to one of Muffet’s affiliated bakeries, and Muffet’s pets will sink their fangs into them, dripping with enough poison to make them sleep for several hours. By the time Sans notices something is wrong, Papyrus will be far away. It’s not an ideal escape plan by any means. He’s gotten himself sick with worry at all that could go wrong several times. God forbid, if they failed—if Sans caught him—

He can’t think like that. They have to risk it. This is the best chance they’ve got.

The souling deserves more than this mockery of love between him and Sans. For his child, he has to try.

“Tell  Muff thanks.” He passes the instructions back over to them. “And thank you guys, too. For everything.”

The spiders chirp up at him.

“Papy?”

Papyrus’ soul squeezes tight in his chest with panic. His caretaker hasn’t returned to his side—Sans has. Pickles and ketchup in hand.

Sweat gathers on his skull. How long had Sans been there? Had he seen Papyrus read the note? Or just the end? Had he seen nothing at all, the spiders obscured by Papyrus himself?

Sans’ ever-present grin betrays no hint of what he does or doesn’t know. Papyrus feels queasy with unease.

“Jeez, sneaking up on me like that.” Papyrus goes for nonchalant. Innocent. “You startled me.”

Sans sets the food aside, crossing over to grab Papyrus in a side hug.

“I’m sorry. Are my two special guys doing alright?”

Sans lays a possessive hand on his stomach. The souling pulses happily at the touch, responding to their father. A few weeks back, the spark of consciousness ignited in the growing child, and intertwined itself with Papyrus. He can feel what they feel, and vice versa. Even now the souling is both happy their father is near, and also bubbling with concern over Papyrus’ anxious state.

“We’re fine,” Papyrus says, reassuring both Sans and the souling. “Just hungry.”

He’s not, really, but it’d look suspicious if he sent his nanny away for food he didn’t actually want. Papyrus takes a pickle from the jar. Holding it like a hot dog, he squirts several lines of ketchup over it. After his first bite, he realizes damn. He actually  _could_  go for a snack right now. He finishes off the pickle quickly.

When he reaches for a second, Sans stops his hand.

“Why don’t we do this somewhere more private? Our bed is more comfortable than these old wooden chairs.”

Papyrus is led back to the bedroom, clutching his pickles close. Along the way, Sans explains that he’d run into the nanny at the kitchens—he’d gotten a quick snack because he was feeling peckish from work—and had taken over her task.

The food is put on the bedside table. Sans hangs up his kingly robe and crawls into bed with Papyrus, cuddling him close and rubbing circles on Papyrus’ belly. Papyrus chows down on a second pickle. Fuck, it’s delicious. Every bite is like the best thing he’s ever eaten.

“I’m sorry I’ve been so busy lately.” Sans says. “There’s so much more work than I’d anticipated that goes into a parade. All the vendors want to showcase their foods and wares, but there aren’t nearly enough slots to accommodate everyone. Not to mention the ferry issues with Waterfall monsters who are having difficulties with passage through Hotland, and the sheer expense of it all…” Sans massages his temple. “But how have you been?”

“Fine,” Papyrus mumbles, licking his fingers clean of ketchup. He’s buzzing with a rare contentment. Sans’ proximity and touch spreads a pleasant warmth in his body. He can feel a familiar itch building in his pelvis. He scowls. Stupid, stupid hormones!

He squirts ketchup onto the next pickle. He shoves it in his mouth, trying to distract himself from his sudden horniness.

Sans watches him with satisfaction.

“Your eating habits have improved tremendously since your pregnancy. I’m glad.”

“Yeah, I just…” Papyrus scratches at his neck. “I don’t want them to be like me. I want them to be strong.”

Sans presses closer, making Papyrus shiver.

“They’ll be healthy and happy. That’s what matters. I won’t let anything happen to them, or you. Never.”

Sans kisses him like he’s sealing the vow.

“Sans, um, could you…do you think you could…” Papyrus squirms, face flushed. He knows exactly what he wants his brother’s nimble hands to do. He wants it but he hates it.

Sans picks up on his distress. “What do you need?”

“I feel…hot.”

Sans’ grin takes on a salacious edge. “Well, I’m sure I could help with that.”

Papyrus’ maternity clothes are loose and comfortable, allowing Sans to easily slip his hand down the waistband of his pants.

Papyrus arches into Sans’ hand as he rubs against him.

“That good?”

“Mmm…” Papyrus lets his head settle against Sans’ chest. Drowsy, aroused, pleasant warmth curling through him. It feels so nice to just lie back and let Sans take care of everything.

Sans slips a finger inside, and works him open slowly before adding a second. They haven’t had full-on sex since Papyrus’ pregnancy was confirmed, but this isn’t the first time Sans has used his fingers to bring him to a fast climax.

Sans murmurs worshipful praises of Papyrus’ beauty as his fingers curl and uncurl inside his wet warmth. Papyrus’ soul pulses. In moments like this, ever so fleetingly, he can almost fool himself into believing that he truly does love Sans.

~*~

Two nights before the parade, Papyrus wakes up screaming.

Sans is shouting, but all Papyrus can focus on is the  _pain_. It feels like a hot iron rod is stabbing him, like it’s being twisted inside him.

He can feel the souling’s shrieks of agony, can feel it ripping magic from him, desperate to live. Papyrus claws at his stomach, primal instincts wanting the parasite  _out_.

His hands are wrenched away, and he screams louder still as he’s restrained. He thrashes, needing to break free, needing to kill this thing inside of him before it kills him.

“Hurts!” He sobs.

He feels both outside himself, an indifferent observer to the scene, but also focused so incredibly inward to the white hot, indescribable pain. Distantly he sees guards rush into the bedroom, magic and weapons ready. One of them crosses over to the bed and lifts Papyrus out.

Something gives inside him, like rubber band that’s been stretched to snapping. His magic level plummets, and he feels—oh god, there’s dust on his pelvis, his legs, spilling onto the sheets, all he can see all he can taste is

Dust.


End file.
